In children, chronic liver disease is a rare but devastating condition. Biliary atresia is a disease of unknown etiology and is the primary indication for liver transplantation in children. Liver disease associated with cystic fibrosis occurs in over 60% of cystic fibrosis patients and is a major contributing factor to morbidity and mortality in cystic fibrosis. Genetic cholestatic liver diseases, such as alagille syndrome, progressive familial intrahepatic cholestasis, mitochondrial hepatopathies and cystic fibrosis associated liver disease are poorly understood and difficult to treat and have significant clinical variability leading to significant morbidity and mortality. Presently, the coordinated study of the etiology and treatment of these rare diseases are organized by the Biliary Atresia Research Consortium (BARC) and the Cholestatic Liver Disease Consortium (CLiC). The formation of a unified and expanded network of pediatric liver disease experts through ChiLDREN will enhance the ability to understand these devastating diseases and discover diagnostic, therapeutic and preventive modalities. As a large, well-organized pediatric liver center in a racially, ethnically and economically diverse region of the South, the Emory- Children's Liver Center will strengthen and enhance the ChiLDREN network. Over the past 10 years, the Emory Liver Center has developed a state-of- the-art system that includes an established electronic record of long term clinical follow up care, a comprehensive database of over 700 hepatology and pediatric liver transplant patients in the region, innovative body magnetic imaging and, in the last year, the establishment of a biorepository now containing over 50 pediatric liver biopsy specimens. The primary Investigator and co-investigators collaborate closely with the Children's Healthcare of Atlanta Cystic Fibrosis Center. The PI has the experience, expertise and infrastructure to carry out collaborative projects and will make substantial contributions to this innovative research and education network, ChiLDREN. Relevance: ChiLDREN will improve the lives of children with biliary atresia, cholestatic liver diseases and cystic fibrosis associated liver disease.